Efeito da troca térmica sobre o processo de ustulação para produção de zinco metálico.

Abstract

Process intensi cation focuses in processes involving mainly liquid-liquid and gas-liquid systems, while solid handling applications are more limited. In this work, the main goal is to propose a complete phenomenological model of the roasting process for metallic zinc production, emphasizing the evaluation of the thermal exchange e ect in di erent points of the process, aiming at increasing the zinc oxide production and steam generation. The model implemented in Aspen PlusTM covers from the roaster feed to the stage of cooling and washing the gases generated by the sul de oxidation reactions. Plant data were used to validate the model results. The results show that the study of alternatives allowing the increase in zinc oxide production and steam generation must take into consideration where the enlargement in thermal exchange area happens. Sensitivity analysis show that, without capital expenditure, operational adjusts make it possible to increase in approximately 10% the zinc oxide production, however, implying in a decrease of around 8,6% in steam generation. With capital expenditure it is possible to obtain operating conditions that increase zinc oxide production up to 25% while also reducing water consumption at the gases cooling stage.